Torquay United loanee Jordan Lee is undergoing tests after suffering chest pains.
The 20-year-old right-back, on loan from Bournemouth, went to hospital with club physiotherapist Gareth Law on Wednesday and now faces some time out.
"When it's chest or heart-related things you've just got to make sure," said Gulls manager Kevin Nicholson. "He's going to go up to St George's Park to have a thorough set of tests, just to make sure there's nothing."
Nicholson told BBC Radio Devon: "I'm pretty sure it's nothing major, but until ourselves and Bournemouth are comfortable that he's 100% then, unfortunately, he's not available to us."